The ability to transfer chat to a human agent is really great, at the time chat only can be transferred to Omni Channel. But not everyone who use Power Virtual Agent will have D365 (and not every D365 project will be using Omni Channel).
Kindly consider and provide some mechanism to transfer to human agents to different channels as well. For example, someone may want chat to be transferred to MS Teams or to a Mobile number as text messages or even to Whats app. Another option can be human agent can be logged in Power Virtual Agent Portal.